Belt drive

Abstract

A belt drive ( 1 ) with belt means ( 4 ), with at least one driving traction pulley ( 2 ), and one driven traction pulley ( 3 ) is provided by the invention, with at least one of the traction pulleys ( 2, 3 ) having a non-circular shape. It has been found that an especially advantageous effect can be made on the vibration behavior of the belt means ( 4 ) and accordingly the belt drive ( 1 ) by the selection of a definite angle of belt contact (alpha) and a constant contact length of the belt means ( 4 ) on at least one non-circular traction pulley ( 2, 3 ). Consequently, the angle of belt contact (alpha) and the contact length are set according to the invention to the one or more non-circular traction pulleys ( 2, 3 ) such that these are nearly constant in each rotational position of the traction pulleys ( 2, 3 ).

1 . Belt drive, comprising belt means, at least one driving traction pulley, and one driven traction pulley, with at least one of the traction pulleys having a non-circular shape, an angle of belt contact (α) and a contact length of the belt means are set to the one or more non-circular traction pulleys, such that the angle of contact and the contact length are nearly constant in each rotational position of the traction pulleys.  
     
     
         2 . Belt drive according to  claim 1 , wherein the angle of belt contact (α) can be determined from a condition  
         α=360°/OZ  
       where OZ stands for an ordinal number of the non-circular traction pulley that is used or for a second, third, fourth, or n-th order traction pulley.  
     
     
         3 . Belt drive according to  claim 2 , wherein the angle of belt contact of α=180° is set for a second order (elliptical) traction pulley.  
     
     
         4 . Belt drive according to  claim 2 , wherein for a third order (triangular form) traction pulley, the angle of belt contact of α=120° or a whole-number multiple of this angle.  
     
     
         5 . Belt drive according to  claim 2 , wherein for a fourth order (rectangular form) traction pulley, the angle of belt contact of α=90° or a whole-number multiple of this angle.  
     
     
         6 . Belt drive according to  claim 2 , wherein for a fifth order (pentagonal form) traction pulley, the angle of belt contact of α=72° or a whole-number multiple of this angle.  
     
     
         7 . Belt drive according to  claim 2 , wherein for a sixth order (hexagonal form) traction pulley, the angle of belt contact of α=60° or a whole-number multiple of this angle.  
     
     
         8 . Belt drive according to  claim 1 , wherein the belt drive connects the crankshaft to the camshaft of a three-cylinder internal combustion engine, and the traction pulley of the camshaft is embodied as a third order (triangular form) traction pulley with the angle of belt contact of α=120° or a whole-number multiple of this angle, and the traction pulley of the crankshaft is embodied with a circular shape.  
     
     
         9 . Belt drive according to  claim 1 , wherein the belt drive connects the crankshaft to the camshaft of a four-cylinder internal combustion engine, and the traction pulley of the camshaft is embodied as a fourth order (rectangular form) traction pulley with the angle of belt contact of α=90° or a whole-number multiple of this angle, or the traction pulley of the crankshaft is embodied as a second order (elliptical) traction pulley with the angle of belt contact being set at α=180°.  
     
     
         10 . Belt drive according to  claim 1 , wherein the belt drive connects the crankshaft to the camshaft of a five-cylinder internal combustion engine, and the traction pulley of the camshaft is embodied as a fifth order (pentagonal form) traction pulley with the angle of belt contact of α=72° or a whole-number multiple of this angle, and the traction pulley of the crankshaft is embodied with a circular shape.  
     
     
         11 . Belt drive according to  claim 1 , wherein the belt drive connects the crankshaft to the camshaft of a six-cylinder internal combustion engine, and the traction pulley of the camshaft is embodied as a sixth order (hexagonal form) traction pulley with the angle of belt contact of α=60° or a whole-number multiple of this angle, or the traction pulley of the crankshaft is embodied as a third order (triangular form) traction pulley with the angle of belt contact of α=120° or a whole-number multiple of this angle.  
     
     
         12 . Belt drive according to  claim 1 , wherein the angle of belt contact (α) can be set by a definite ratio of dimensions of the traction pulleys and/or through a selection of a spacing of the pulleys relative to each other and/or by deflection pulleys, deflection rolls, or guide rails.  
     
     
         13 . Belt drive according to  claim 5 , wherein for the fourth order (rectangular form) traction pulley, the angle is set at α=180°.  
     
     
         14 . Belt drive according to  claim 6 , wherein for the fifth order (pentagonal) traction pulley, the angle of belt contact is set at α=144°.  
     
     
         15 . Belt drive according to  claim 7 , wherein for the sixth order (hexagonal) traction pulley, the angle of belt contact is set at α=120°.